Question

a water molecule has a mass of 2.99 × 10^-26 kg. written in scientific notation, which is the best estimate of the mass of 1.2 × 10^6 water molecules? 3 × 10^-20 kg 3 × 10^32 kg 3 × 10^-32 kg 3 × 10^20 kg

Explanation:

Step1: Multiply the coefficients and add the exponents

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Step2: Calculate the coefficient and exponent separately

• Coefficient: \(2.99\times1.2 = 3.588\approx3\)
• Exponent: Using the rule \(a^{m}\times a^{n}=a^{m + n}\), so \(10^{-26}\times10^{6}=10^{-26 + 6}=10^{-20}\)

Answer:

\(3\times10^{-20}\text{ kg}\)